This invention relates to a process for pan granulation, a simple and novel mechanical configuration, and operation of the pan. The granulation process can be used with binders to produce narrowly sized granules of superior hardness and density with high efficiencies and production rates.
There are many patents in the prior art such as U.S. Pat. Nos. 3,711,254; 4,589,904; 4,743,289; D.E. 3,623,321; U.S.S.R. SU 1,567,558; DD 243,274; U.S.S.R. SU 1,468,890; PCT Int. Appl. WO 89 04,291-U.S. application Ser. No. 15,920 (Nov. 02, 1987). All these patents use different processes and mechanical arrangements to carry out granulation, yet almost without exception these patents are specific to one product, as with U.S. Pat. No. 3,711,254 or U.S.S.R. SU 1,468,890, both of which are specific to potash. In addition, the low yields of 20-50% experienced and claimed (e.g. U.S. Pat. No. 3,711,254) and the complexity of the mechanical circuits (previous citation) indicate that there is not an adequate understanding of the chemistry, physics and mechanical equipment in the current art to provide industry with the right technology.
Some patents have used the notion of a seed about which a core can be built up to produce a granule, such as U.S. Pat. No. 3,711,254 for potash or DE 3,623,321 for sugar. Neither patent teaches that if the process concept and mechanical flowsheet are properly done, a whole range of industrial materials can be economically granulated in high yield. The plethora of patents in the area of granulation along with the comparatively narrow range of products suitable for each patent is testimony to the need for a simple and effective system that can granulate a wide range of materials.
The objects of the invention are to achieve superior economic performance in the preparation of narrowly sized particles for a wide range of industrial materials. The narrowly sized particles can be produced over a wide span of granular mesh size ranges.